The Stovebolt Site Forums The Shop Area Engine Shop Camshaft bearings

Ok, ran into another roadblock. When I pulled the cam it looked OK. Normal wear pattern on the lobes (all smooth surfaces), didtributor gear looked fine, spun freely in the block and the cam journals looked OK for an old cam. Later when I looked at the front bearing it didn't look to good, see the pic. Only the front had wear marks but the two intermediate bearings looked "tarnished", see the pic, and the rear bearing looked OK. Also attached a pic of the front journal on the cam, the other three look similar.

So here's my question, can I just replace the cam bearings or is a cam and lifter set in my future?

Fortunately, stovebolt cam bearings aren't under a bunch of load. The valve spring pressure is pretty low, and the rocker arms don't have a very high ratio (about 1.5:1) If the bottoms of the lifters aren't worn cupped and you have kept them with the same cam lobes they've been in contact with, the valve train can probably be reused. That being said, you can definitely improve the engine's power and torque with a new Melling CCS-1 cam and a new set of lifters, if your finances allow for the cost. A new cam and lifters will probably cost around $300.00. Add a new set of cam bearings to complete the valve train rehab.

The CCS-1 cam has a somewhat longer exhaust valve duration than the factory cam that was used in the 235 Corvette engine and the 261 medium and heavy duty trucks- - - -which was a bit more radical than the normal 235 cam. By increasing the "valve open" time of the exhaust, there is better cylinder scavenging and more low end torque, without creating an objectionable idle lope and loss of intake manifold vacuum.
Jerry

My thought is you can just replace the cam bearings. But checking the cam journal diameters would be good. If those are worn significantly, then maybe the cam should be replaced.

Jerry's caution about keeping lifters in the same spot on the cam if reused is important.

Be certain to get the thrust plate clearance to camshaft as low as possible (.001 to a max of .003"). What will happen if that clearance is too much is at low (idle) rpm the cam will walk forward and backward on you. It stops at around 8 or 900 rpm but when it happens, it will alter your ignition timing enough to make your idle not be smooth. If you have clearance of .010" or greater you will notice this quite a lot.

Oh, and my lifters look like this, don't see anything like them listed anywhere.

Well good news and bad news. Cam journals are just fine. While a quick look at the lifters says they're ok, a straight edge does conform that they are concave, not crowned outward as intended.

I did find the CSS1 for about $150 but lifters seem to be the big ticket item. Anyone have a source, or alternate part number than original? Kanter has the milk can type listed for $24 each, other suppliers much more.

Those lifters can be reground, so don't trash them. Unless they're severely cupped, it's possible to put the proper contour back on the bottom with a pretty simple radius-grinding device in a lathe. I should have my lifter reconditioning setup in operation before too much longer, if some family medical concerns will let me get back to shop projects soon.
Jerry

OK, didn't measure the cup only checked with a straight edge looking at a light. Didn't look severe. I'll measure a couple and post what I find. Not in a huge rush, I'm leaving town for a cople of weeks and there's plenty to do before I get to lifters.

Those are "soda bottle" lifters. They're supposed to be "milk can" lifters. LOL!

Take a real soft scotch-brite pad and clean up those cam bearings along with some degreaser. The white pads are the softest. You will likely find the bearings will look really good once cleaned up, the front one will still have grooves from the wear, think of them as oil grooves and move on.

So, I used a straight edge and feeler guages to see how bad the dip is on my lifters. Only did six random ones. One measured .002", three measured .003" and two measured .006". IF they are all in this range are they candidates for regrinding?

Also, klhanen referred to the lifters I have as "Soda bottle" lifters. I've seen NONE of what I have for sale anywhere, just the "milk can" type. Are "Soda bottle" and "milk can" lifters the same dimensionally? Should I need to go the "Milk can" route just want to know if pushrod length will be an issue. Thanks!

The "milk can" lifter has a mushroom-shaped pushrod seat that projects up into the side cover area, and uses a shorter pushrod. The later engines use a lifter that's a little shorter, and does not have the odd shaped top. Those shorter lifters are available on Ebay pretty often. The amount of wear you've measured is well within the possibility of regrinding, however. The price of both types of lifters has gotten outrageous!

www.ebay.com/itm/256404768741?

Jerry

Yes, those lifters are pricey, but what can we do. Just to clarify, I'll be able to use the same pushrods with the later '56 - '62 lifters if I end up needing to get new ones, right? When I bought new rockers and shafts I had to replace some pushrods as well. Hoping that wasn't a waste. Thanks!

You should watch useing different style lifters. i don't know about the chev motor, but i ruined 3 cams in my 270 GMC before i realized that i had the wrong lifters for my cams. the milk can style ate up 3 cams in no time. i went to a later model chilled iron lifter and that solved my cam problem. by all means resurface your old lifters they and the cam must like one another and will live a long time.

All of the new cams for stovebolts that I'm aware of are cast iron- - - -not forged steel like the 216 and early 235 engines ran. They require a different alloy of lifter, like Jay mentioned. Even the Melling CCS-12 which is sized for the 216 engine has a cast iron core, and it requires the later model lifter alloy.
Jerry

That was a joke. I called them that because you stuck one in a soda bottle for the picture. I've never seen one like that before. Sorry if I got you off on the wrong track.

If those lifters worked with your current cam and the cam isn't worn, then you should be able to reuse them after regrinding.

There's also the issue with using the right distributor gear with the cam. Jerry has mentioned in the past that using a distributor that was on a steel cam with a cast cam can cause problems. Also the other way around.

yes, on the dist gears. a while back i built an hei dist for my 270 and was getting ready to put the gear on and noticed i had a new brass gear on the shelf, it lasted about 35 hiway miles the gear was completely ground off.

To klhanen, nice but it wasn't a soda bottle. it was a bottle of "Smart Water", see the pic. Before anyone get's excited, my wife has assured me it has no positive effects, a placebo I guess : )

I looked into the cam material and lifter compatability. From what Jerry said and what I found is that my old cam should be a cast cam and so later lifters OR my re-surfaced lifters should be fine.

Will be away from home for a couple of weeks so the project will sit for a couple of weeks. Thanks again!

Cast and forged parts such as crankshafts and cams have a different appearance, one that an experienced machinist can recognize by look and feel. Cast items will have a thin, straight parting line where the molds met, while a forged part will have a wider, ground flat area where the excess material was cleaned up after the forging process was roughed out. Steel and cast iron also produce a different shape and color of sparks when touched to a grinding wheel.
Jerry